What Iran is proposing and the 60-day timeline

Tehran announced on 18 June 2026 that it intends to introduce a system of maritime fees for commercial vessels passing through the Strait of Hormuz, as reported by the Guardian. The fees would take effect at the end of a 60-day negotiation period triggered by the signing of a memorandum of understanding between the US and Iran.

The Iranian government described the move as a historic assertion of sovereignty, stating that the strait is under its control and that the charges would cover the cost of managing the waterway, according to the Guardian's report. No specific fee schedule has been published. The absence of detail is itself a problem for operators trying to model exposure; whether charges are levied per vessel, per deadweight tonne, or per barrel of cargo will determine the scale of the impact.

Approximately 21 million barrels of oil per day transit the Strait of Hormuz, representing roughly 21% of global petroleum liquids consumption, according to US Energy Information Administration data. The waterway is also a conduit for liquefied natural gas cargoes and container traffic serving Gulf ports. Even a modest per-barrel or per-tonne charge compounds rapidly at that volume.

The 60-day window places a provisional deadline around mid-August 2026. Businesses with freight contracts, energy procurement agreements, or supply chain commitments extending beyond that date face a period of material uncertainty.

How Hormuz fees could affect UK freight and energy costs

The most direct transmission mechanism is through tanker freight rates. Shipowners and charterers will seek to pass any new Hormuz transit cost on to cargo owners, which in turn feeds into the landed cost of crude oil and refined products arriving at UK terminals.

Brent crude has already moved on speculation about Hormuz access restrictions during 2025 and into 2026. A formalised fee regime would add a structural cost layer on top of existing geopolitical risk premiums. The magnitude depends on the fee level, but even a charge equivalent to a few cents per barrel would translate into tens of millions of dollars per day across total strait traffic.

For UK manufacturers, the concern extends beyond direct fuel bills. Petrochemical feedstocks, plastics, fertilisers, and other energy-intensive inputs sourced from or priced against Gulf production would all carry the additional cost. Logistics operators running supply chains through the Suez Canal and onward through the Gulf face a compounding effect: Suez Canal tolls plus a new Hormuz charge.

Container and general cargo traffic

The strait is not only an oil artery. Container vessels serving ports in the UAE, Bahrain, Qatar, and Kuwait also transit the waterway. UK importers of goods from those markets, including construction materials, aluminium products, and consumer electronics routed through Dubai's Jebel Ali port, should expect freight rate adjustments if the fees proceed.

Shipping lines typically respond to new cost inputs through bunker adjustment factors or congestion surcharges. A Hormuz transit fee would likely be passed through in a similar mechanism, appearing as a line item on freight invoices within weeks of implementation.

European naval mission rebuffed: implications for shipping security

Tehran simultaneously rejected a proposed European naval escort mission for the strait, asserting that foreign military operations in the waterway are unwelcome, according to the Guardian's report.

The UK has direct experience of naval operations in the region. The International Maritime Security Construct, a UK-led coalition, was established in 2019 after a series of tanker seizures and attacks in the Gulf. That mission aimed to guarantee freedom of navigation for commercial shipping. Iran's rejection of a new European initiative raises questions about whether similar guarantees can be maintained.

For commercial operators, the security dimension matters because it feeds directly into insurance costs. War risk premiums for vessels transiting the Gulf have fluctuated significantly in recent years. If naval escort options are curtailed and Tehran's sovereignty claim goes unchallenged, insurers may reassess the risk profile of Hormuz transits. Higher war risk premiums would add another cost layer on top of any transit fees.

The UK government has not yet publicly responded to Iran's rejection of the European mission. The Ministry of Defence's posture on Gulf naval operations will be a factor in how Lloyd's of London and other marine insurance markets price Hormuz risk in the coming weeks.

What operators should review in contracts and procurement now

The 60-day window is not long. UK businesses with exposure to Hormuz-dependent supply chains should be reviewing several areas immediately.

Freight contracts and surcharge mechanisms

Existing freight agreements may or may not allow carriers to pass through a new sovereign transit fee. Operators should check whether contracts contain provisions for government-imposed charges, canal or strait tolls, or regulatory cost adjustments. Where contracts are silent, renegotiation or clarification before mid-August is prudent.

Energy procurement

Businesses on fixed-price energy contracts may be insulated in the short term, but those purchasing on floating or index-linked terms will see any Brent crude increase flow through relatively quickly. Finance directors should model the impact of a $1 to $5 per barrel uplift scenario on their energy costs, recognising that the actual fee structure remains unknown.

Force majeure and hardship clauses

A new transit fee is unlikely to trigger force majeure provisions in most standard contracts, as it does not prevent performance. However, if Iran were to restrict or delay transit for non-paying vessels, the picture changes. Operators should review whether their contracts distinguish between impossibility and mere cost increase, and whether hardship or material adverse change clauses offer any relief.

Insurance

Marine cargo insurance and war risk policies should be reviewed for exclusions or premium adjustment triggers linked to sovereign actions in the Gulf. Brokers at Lloyd's and in the London market will be watching the 60-day period closely.

Alternative routing

For some cargoes, alternative sourcing or routing may be worth modelling. Crude oil from West Africa, the North Sea, or the Americas does not transit Hormuz. LNG from the US Gulf Coast avoids the strait entirely. The cost differential between Hormuz-dependent and Hormuz-free supply chains may narrow if fees are set at a meaningful level.

None of these steps require predicting the outcome of the US-Iran negotiations. They require acknowledging that a new cost input is plausible within 60 days and preparing accordingly. The businesses that model the scenarios now will be better positioned than those that wait for a fee schedule to be published.